Turbo vs Super. was variable comp...variable disp....

[xxalexx at ix.netcom.com]

> Date:          Sun, 22 Feb 1998 14:04:12 -0500
> From:          Clare Snyder <snyder at huron.net>
> Organization:  Snyder Enterprises
> To:            diy_efi at efi332.eng.ohio-state.edu
> Subject:       Re: Turbo vs Super. was variable comp...variable disp....
> Reply-to:      diy_efi at efi332.eng.ohio-state.edu

> xxalexx at ix.netcom.com wrote:
> > 
> > > From:          "Espen Hilde" <mwichstr at online.no>
> > > To:            <diy_efi at efi332.eng.ohio-state.edu>
> > > Subject:       Re: Turbo vs Super. was variable comp...variable disp....
> > > Date:          Sat, 21 Feb 1998 03:26:59 +0100
> > > Reply-to:      diy_efi at efi332.eng.ohio-state.edu
> > 
> > > The fameous Merlin engine used a turbine that was coupled to the crank
> > > shaft.
> > > Some Scania diesel engines to.
> > >                 Espen
> > Known as turbo compounding, also allows use of supercharger,
> > developed in WWII before jets and turbines took over power
> > when discovered pistons not needed.
> >   Alex
> 
> I BELIEVE HE WAS REFERRING TO THE CENTRIFUGAL SUPERCHARGER, in
> comparison to the positive displacement type supercharger commonly
> referred to. The centrifugal unit works like a turbocharger, but is
> shaft driven instead of exhaust turbine driven. Works good for low boost
> (altitude compensation, for example).  It does not provide a "positive
> boost" like a positive displacement unit.
> -- 
>                           
I do not know of any airplane engine that uses a ROOTS blower.
(true positive displacement would uses pistons like a shop air 
compressor)Roots, Paxton , axial, centrifugal blowers are designed 
for flow not pressure.  
Connecting the exhaust turbo too crankshaft is more efficeint than
compressing the air.
 I think capable of 40 lbs boost at takeoff using water injection
for war time emergencies.  They still use WWII airplane engines
in unlimited airplane races, and boat races, turbine thou is
showing up.  
Alex